Background: Grandmothers in the "sandwich generation" are considered as those women who are potential caregivers for two generations: older relatives and grandchildren. Methods: With the goal of understanding the factors that affect their stress and health, 149 women from southwestern Spain were interviewed using an ad hoc questionnaire that included standardized scales and subscales. Results: The results showed that age, coping strategies based on emotional support and acceptance, as well as optimism and social support improved the health of these women by reducing their perceived stress. Although caring for older relatives is related to family conflicts and worse health, conversely, caring for grandchildren is related to slightly better health. Conclusions: The results are useful for planning psychological interventions with these women and highlight the need to include family interventions.